ABSTRACTPremenstrual symptoms have been reported to be highly correlated with levels of perceived stress; however, the magnitude of the relationship remains unclear. The purpose of the study was to identify the relationships among perceived stress, acculturative stress, and premenstrual symptoms. The study used a 10-week longitudinal web-based design. A total of 98 female Korean international students studying in the U.S. and 89 Korean domestic students studying in South Korea were recruited using convenience sampling. Data collection was conducted between November 2014 and February 2015. The participants completed 10 weekly web-based surveys. Data were analyzed through descriptive analyses, linear multivariable mixed model regressions, t-tests, and hierarchical multiple regressions. The levels of both perceived stress and menstrual-related symptoms were higher during the premenstrual phase in Korean international students than in domestic students (p < .001). In Korean international students, perceived stress (β = 0.30; p < .001) and acculturative stress (β = 0.26; p < .01) were the most strongly related factors to the severity of premenstrual symptoms. Although perceived stress was significantly related to the symptoms in Korean domestic students, a history of sexual abuse was the strongest related factor (β = −0.28; p < .001). Because stress is a potentially modifiable factor, understanding its relationship to premenstrual symptoms can contribute to relieving these symptoms.